On 07/06/2011 04:23 PM, asinghal@xxxxxxxxxxxxxx wrote: > We plan to use high resolution timers in one of our modules, with the > requirement that we cancel these timers when the cpu goes idle and restart > them when the cpu comes out of idle. > > We are cancelling the timers in cpuidle prepare callback. The problem is > that if the need_resched() call in drivers/cpuidle/cpuidle.c returns true, > how do we restart the timer? If the call returns false, we can restart the > timer in the cpuidle enter callback. Hi Amar, I think you should not use cpuidle prepare callback at all. It may be removed soon (see https://lkml.org/lkml/2011/6/6/261) and I think there are better ways to achieve what you are trying to do. I think everything should go into the enter routines (the idle routines provided by the driver). That way you would not have to worry about need_resched() in cpuidle.c. Also it would be a cleaner implementation as you wouldn't touch generic cpuidle code. > > The solution to the problem that we have in mind is adding an unprepare > callback to the cpuidle_device struct, and calling it if needs_resched() > returns true. Another option is to implement deferred timers for hrtimers. > Which of the two options is the better solution, or is there another > feasible alternative? As i said, everything should go inside enter routine and you wouldn't have to use/implement prepare/unprepare callbacks. Thanks -Trinabh _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
